By Ifeoluwa Adenike Alade, PhD candidate, University of Ibadan, Nigeria
Food and nutrition insecurity is a chronic problem for Africa. Despite decades of humanitarian and development efforts, one in five Africans remain undernourished and a third of Africa’s children are stunted.
One little-known crop that is essential to food security on the continent is amaranth. This leafy green vegetable is one of the most consumed in Africa and accounts for up to 25 per cent of daily protein intake in some countries, making it essential to their health and wellbeing.
What’s more, it is a plant that is quick to grow, thanks to its highly efficient photosynthesis process, and which thrives on degraded land even in hot and dry weather, making it an increasingly important crop to mitigate the impact of climate change on food production.
But one threat that holds back amaranth from making an even greater contribution to Africa’s food security is the amaranthus leaf webber, a species of moth that is commonly found in the tropics. The webber larvae are voracious pests, and a single leaf webber infestation can destroy an entire field of amaranth.
To prevent an infestation and protect their amaranth harvest, farmers rely on pesticides. However, long-term pesticide use comes with challenges, including the development of resistance among leaf webbers.
So, what if farmers had another tool to stop this pest?
This question motivated me to search for new crop protection techniques that could be affordable, effective, and sustainable, and it turns out that nature may have already come up with a solution.
Many plants have evolved ways to deter pests through releasing biochemicals that repel harmful insects. By identifying the biochemical that targets leaf webber and reproducing this as a crop protection product, we can effectively safeguard crop harvests using the plant’s own biochemistry.
For amaranth farmers, plant-produced repellents could be valuable new tool in the toolbox, supported by other strategies such as pest monitoring and surveillance, using complementary crops to repel pests and using existing pesticides when necessary.
Taken together, such integrated pest management (IPM) can dramatically improve yields while also reducing labour and costs, by ensuring that farmers use the most effective and sustainable combination of crop protection techniques.
To progress this research, I am studying leaf samples of a group of amaranth species to compare the levels of biochemicals with the abundance of leaf webbers. If leaf webbers are less abundant on plants with certain biochemicals present, then I will have detected a possible repellent.
The next stage involves examining the genetic make-up of the amaranths that produce these repellents to discover the blueprint for the most pest-resistant variety.
Crop scientists can then develop a species that is no longer vulnerable to this pest. This would be a huge boon for Africa’s food security, especially in the rural areas that rely on amaranth, protecting both nutritious food supplies and agricultural livelihoods.
Such a solution is an example of how crop protection can be proactive rather than reactive when it comes to defending vital crops against pests.
And as one of the next generation of crop scientists, my work is just a small part of an increasingly innovative sector.